Speed-reducing control



Aug. 14, 1928;

A. E. H. GRAVILL ON SPEED REDUCING CONTROL F ed Oqt. 23. 1926 ATM/9M5! v Patented Aug. 14, 1928 UNITED STATES 1,680,874 PATENT orl-"filpcr.1;*-

'AUGUSTE EUGENE 11mm .GRAYILLON, or. PARIS, FRANCE.

SPEED-REDUCING common.

Application filed October 23, 192e,sm1 no. 143,771, and in France November 4, 1925.

The object of my invention is to provide a single or double speed reducing con trol more especially suitable for variable air:

condensers butalso usable wherever a movable part or a set of'movable parts is desired bination with the main control that rotates.

the" movable part of the apparatus or instrument at an unreduced speed (an operating knob in the particular caseof variable condensers for radio instruments), of an auxiliary control connectedwith the said main control through a suitably guided flexible shaft or such like. This shaft may or may not be provided with an intermediate speed reducing device, and its free end carries a suitable movable friction part which bears on a fixed member that may or may not be part of the instrument, such connection permitting .the .main operating control and, hencc the movable part of the instrument to be driven at a speed proportional to the diameter of the above mentioned friction art.

Figures 1, 2, and 3 of the accompanying drawing are vertical sectional views of three embodiments of the invention, all three being based upon the same principle.

The control device shown by Figure 1 is especially designed for ready fitting on any type of variable air condenser for radio sets.

is fastened on an inner tube F, by means of V which latter it is secured on spindle A, said knob E permitting blades B to be rapidly moved.

According to my invention, the knob E is formed with a passage through which extends a rigid tubular member G, of bent shape, rigidly attached at one end to tube F and terminating at the other end at H beneath the dial portion I of said knob. Within said tubular member G is housed a flexible shaft J, preferably comprising two portions the spirals of which run in opposite directions so as to reduce over-suppleness which might hinder perfect control efliciency. On

the end K of flexible shaft J is secured a small operating button L, while on its other end is secured a roller M bearing with suitable pressure on panel D.

The operation of this device will now be readily understood .When I turn the main knob E, I obtain rapid displacement of, blades 'B. If I wish the blades to be actu ated at a reduced speed, I merely have to turn the auxiliary knob or button L,whereby theflexible shaft J is rotated and, in turn, rotates roller M. vSincethis roller bears on the fixed panel I), there will be produced an extremely slow motion of the main knob E and, hence, of spindle A andblades B connejcted thereto. p

In the example shown by Figure 2, the flexible connection J runs through spindle A, on which are mounted the movable blades B, and the roller M comes to'bear on the lowercheek plate G of the condenser. The operation of this device is analogousto the one of Figure 1. V f

The embodiment illustrated by FigureB' offers the peculiarity of comprising a double speed reduction. For this purpose, the auxiliary operating knob or button L has a small bevel pinion N meshing with a larger bevel pinion O secured to the flexible shaftJ, which latter, as in the preceding case, has a terminal roller M that bears on the fixed panel D. A spring P, or'any other suitable contrivance, keeps parts N and O in mesh for driving the flexible shaft. As will be realized, the speed transmitted to spindle A is, therefore, reduced a first time by parts N and O and a second time by friction roller M.

The speed reducing device N--O can be positioned at any point on the flexible shaft, and in any and all cases the friction part M can be constituted by a toothed wheel meshing with a circular rack provided forthe purpose. i i

I wish it to be clearly understood that I reserve the right to modify or alter the above described speedreducing devices or parts according to the particular uses for which they may be intended without being deemedto depart from the scope of my in- Vention.

I claim as my invention:

1. A speed-reducing control for instruments embodying a movable part and a spin dl whereto such part is attached, comprisof the transmission element to engage and move over a stationary part of the instrument and thereby reduce the speed of rotaelement.

tion of the main knob by said transmission 2. A speed-reducing control for instrm ments embodying a'movable part, compi'is-T ing a main rotary operating element con nected to drive the movable part at unreduced speed when idirectly actuated, and

-2 having a passage formed through it; an

auxiliaryv rotary operating element; a rigid tube mounted 1n said passage and securely connected at one end with the main operating element; a flexible shaft passing through said tube and projecting beyondthe same at opposite ends, one end being attached to the auxiliary operating element to berotated by the same andto transmit such rotationto the main operating element; and

a friction n emberon the other end of said shaft to engage. and move over a stationary. part of theinstrument and thereby reduce the speed of rotation of the main knob by the shaft.

3. 'A speed-reducing control, accordingtol claim 2, which a rigid tube ismounted in" a passage formed throu h the main knob,

through and beyond which tube the I flexible transmission element extends, said tube being fastened atone end to said main knob.

4. A s eed-reducing control for instruments em odying a movable part, comprising a remain. rotaryv'tz. operating element connected to drive the movable part at unreduoed-'- speedwhen directly actuated; an auxiliary operating element for said movable part; aflexible shaft connection between the auxiliary and main operating elements for transmitting the rotary movement ofthe Qforiner to the latter at a reduced speed; and means associated with said shaft for reducingthe speed of rotation ofthe main operating elementiby the shaft.

5. A speed-reducing control for instru merits embodying a movable part, comprising a main rotary operating element connected to drive the movable part at unreduced speed when directly actuated; 'an' auxiliary operating element for said movable'part; a flexible shaft connection between the' auxiliary and main operating elements for transmitting the rotary movement of, the former to the latter; and a friction element'associated with said shaft to engage and move over a stationary part of the instrument and thereby reduce the speed of rotationofthe main operating element by the shaft. f

(i. A speed-reducing control, according to claim 5, inwhichthe friction element comprises a roller atta'chedto the flexible shaft and engaging a stationary part of the instrument. I

In testimony whereof I afiix my signature. v AUGUST]! EUGENEHENRI GRAVILLON. 

